The present invention relates to a polishing composition which is used, for example, in final polishing of a silicon wafer, and to a polishing method using this polishing composition.
As a conventional polishing composition used in final polishing of silicon wafers, the polishing composition disclosed in Japanese Laid-Open Patent Publication No. 4-291722 is known. This polishing composition contains a nonionic surfactant of which the HLB value is no less than 13 and less than 20, so that the haze on the surface of the silicon wafer after polishing is suppressed. As the nonionic surfactant of which the HLB value is no less than 13 and less than 20, the publication discloses nonylphenol to which ethylene oxide is added, para-cumenyl phenol to which ethylene oxide is added, primary alcohols of which the carbon number is 12 or 13 to which ethylene oxide is added, block polymers of ethylene oxide and propylene oxide and the like. Polishing compositions containing these nonionic surfactants, however, do not have satisfactory performance as currently required in terms of suppressing haze on the surface of silicon wafers.